Several different types of culture are routinely performed. The Classification of tissue cultures is based on the origin of the cells; which can roughly be divided into "primary culture" and "culture of established cell lines." Primary tissue culture can consist of the culture of a complex organ or tissue slice, a defined mixture of cells, or highly purified cells isolated directly from the organism. Compared to a cell line using primary culture has the advantages in that they are recently removed from the in vivo situation and therefore is expected to more closely resemble the function of that cell or tissue in vivo. However the disadvantage of primary culture is that these cultures are reacting to a constantly changing environment over the first few days in vitro. This includes the damage sustained during the removal of cells from the animal and tissue and partial recovery from this damage, the change in environment from the animal to the in vitro culture, and the changing composition of the culture as some cells in the mixed cultures die and others proliferate and/or differentiate. [1]
The different techniques used in primary tissue culture There are two basic methods of primary cell culture; explant culture and enzyme dissociation.
Explant culture is a small piece of tissue extracted from a live source that is attached to glass or treated plastic culture vessel with added culture medium. Within a few days the individual cells will move from the explant out on to the culture vessel’s surface/substrate where the cells will start to divide and grow. [2]
Enzymatic dissociation is the second method and is more commonly used. The enzymatic dissociation speeds up the explant culture by the addition of digesting enzymes. The digesting enzymes are usually trypsin or collagenase and they work by dissolving the tissue fragments and the cement holding the cells together. This creates a suspension of single cells that are placed into